Field of the Disclosure
The present disclosure generally relates to a semiconductor apparatus.
Description of the Related Art
In a semiconductor apparatus, polycrystalline silicon is used as a resistor or wiring. A technique for improving stability of a resistor value by arranging silicon nitride above a polycrystalline silicon resistor is discussed in Japanese Patent Application Laid-Open No. 2008-227061 and Japanese Patent Application Laid-Open No. 2006-222410. In the technique discussed in Japanese Patent Application Laid-Open No. 2006-222410, two nitride films, i.e., a first nitride film 29 and a third nitride film 43, are disposed above a resistor element 21 including a polycrystalline silicon pattern. Further, in the technique discussed in Japanese Patent Application Laid Open No. 2006-222410, contact holes for electric connection are formed on an interlayer insulation film 27 and a first nitride film 29. When the contact holes are formed through the technique discussed in Japanese Patent Application Laid-Open No. 2006-222410, etching has to be applied on the two nitride films, i.e., the first nitride film 29 and the third nitride film 43. This degrades reliability of the electric connection to the polycrystalline silicon pattern, and eventually degrades reliability of the semiconductor apparatus.